Answer:
![w = 6b](https://img.qammunity.org/2021/formulas/mathematics/high-school/twip3roiivts3i4dkktwfxinx9y308b3kg.png)
Explanation:
Given
![b = blood](https://img.qammunity.org/2021/formulas/mathematics/high-school/hv7h70eehnjm2146ilmwtf2ophtgn6i2lk.png)
![w = weight](https://img.qammunity.org/2021/formulas/mathematics/high-school/xnjxknbqp6rec8j31xsg9svtkslk64sbd8.png)
![b = 20; when\ w = 120](https://img.qammunity.org/2021/formulas/mathematics/high-school/utwb9qeherk4ql94b5xs27tftd30clawey.png)
Required
Determine the equation that binds both parameters
First, we need to determine the constant of proportionality using:
![w = k * b](https://img.qammunity.org/2021/formulas/mathematics/high-school/yr5suakh45eepdgk5iu931ltt82u6ch4qs.png)
Where k represents the constant.
Substitute 120 for w and 20 for b
![120 = k * 20](https://img.qammunity.org/2021/formulas/mathematics/high-school/ojfin58s7lmiemcen46esaxnxfdymlowm1.png)
Divide both sides by 20
![6 = k](https://img.qammunity.org/2021/formulas/mathematics/high-school/tini0m4cw3gtlev96tzg3fjqx1inw5fr1y.png)
![k = 6](https://img.qammunity.org/2021/formulas/mathematics/middle-school/r855jgi5v7tyedmrathv0j18s98z6vfebr.png)
Using the same formula, substitute 6 for k
![w = 6 * b](https://img.qammunity.org/2021/formulas/mathematics/high-school/makm7317wp6xggtionrjdjqeru8cwaeznl.png)
![w = 6b](https://img.qammunity.org/2021/formulas/mathematics/high-school/twip3roiivts3i4dkktwfxinx9y308b3kg.png)
Hence:
The equation is represented as
![w = 6b](https://img.qammunity.org/2021/formulas/mathematics/high-school/twip3roiivts3i4dkktwfxinx9y308b3kg.png)